Fast growing broiler production from genetically different pure lines in Turkey. 2. Broiler traits: growth, feed intake, feed efficiency, livability, body defects and some heterotic effects.

The aim of the this study was to reveal the trends in body weight (BW), feed intake (FI), feed conversion ratio (FCR), livability, and body defects (foot pad dermatitis (FPD), hock burn (HB), and breast burn (BB)) in offspring of ANADOLU-T pure lines (PLs), their 12 four-way hybrids and ROSS-308 hybrid, and the observed heterosis values for some performance and body defect traits. A total of 2736 (1368 broilers each) broiler chickens from ANADOLU-T pure lines, their hybrids, and commercial ROSS-308 hybrid were hatched from breeder eggs at 32 and 52 weeks of age and reared for 42 days in 2 experiments. The PL eggs were generally heavier than hybrid eggs (P < 0.001) and day-old BWs (P < 0.001) were also higher in PL chicks (ranging between 44.5 and 45.8 g). The males of ROSS-308 hybrid were heavier than others at 42 d of age (P = 0.035), and the lowest BW values were determined for A1, A2, and A3 line chickens (P < 0.001). ROSS-308 (4453.8 g) showed similar 42-d FI with all of four-way ANADOLU-T hybrids except (B1 × B2) × (A1 × A2) and (B1 × B2) × (A3 × A1). The 42-d FCR was 1.473 for the ROSS-308, while it ranged between 1.654 and 1.715 for the four-way ANADOLU-T hybrids (P < 0.001). The 42-d livability of four-way ANADOLU-T hybrids and ROSS-308 ranged between 92.0 and 100.0%. All ANADOLU-T hybrids, except two, showed higher 42-d livability than ROSS-308. While both genotype and sex were important for HB and BB, only the genotype effect was significant for FPD (P < 0.001). All ANADOLU-T hybrids showed low to moderate and positive heterosis for BW after 28 d. From 14 to 42 d, the magnitudes of heterosis for FCR decreased. Heterosis for livability from 7 to 42 d were not significant between genotypes. Percentages of heterosis for resistance to FPD (- 1.56 to 1.44%), HB (- 37.03 to 18.75%), and BB (- 12.70 to 1.02%) defects were not significant among genotypes. It was concluded that mating of B1 × B2 males with A1 × A2 and A3 × A2 females seems more favorable in terms of higher chick and meat production. However, the fact that the overall performance of ANADOLU-T hybrids is lower than ROSS-308 clearly indicates that genetic selection must be maintained for enhanced body weight and feed efficiency.

Fast growing broiler production from genetically different pure lines in Turkey. 1. Parental traits: growth, feed intake, reproduction, and hatching traits.

The aim of the present study was to reveal the trends in age-related growth, feed intake, reproduction, and hatchability traits in 5 pure line (PL) breeders (3 dam [A1: slow-feathering, A2: fast-feathering, A3: slow-feathering] and 2 sire [B1: fast-feathering, B2: fast-feathering]) and their reciprocal two-way cross parent stock (PS) breeders (6 female [A1♂ × A2♀; A1♂ × A3♀; A2♂ × A1♀; A2♂ × A3♀; A3♂ × A1♀; A3♂ × A2♀] and 2 male [B1♂ × B2♀; B2♂ × B1♀]) and to identify heterotic effects in two-way cross PS combinations showing superiority over PL breeders. In the rearing period, 60 females and 15 males in the each PL group, 120 females in each female PS and 120 males in each male PS breeders, and 40 females and 5 males were used in each PL and PS genotype in the laying period. Body weight (BW), average daily feed intake (ADFI), reproductive traits (age at first egg [AFE], age at sexual maturity [ASM], egg number, weekly and total %Lay, egg weight, egg mass), hatching traits (fertility, hatchability of fertile [HOF] and set [HOS] and embryonic mortality), and heterosis (%) values for some traits were assesed. Both males and females of PLs and PSs had different BW at 4 and 8 weeks of age (P < 0.01), but had similar BW from 12 to 24 weeks of age. The A2, B1, and B2 hens had a higher BW (nearly 4000 g) than the others at 31 weeks of age (P < 0.01), and B2 hens showed a BW of more than 5000 g at 64 weeks (P < 0.001). Weekly ADFI per female in rearing, laying, and overall period was not different between groups. The A1 (179 days), A3 (183 days), two-way cross (from 175.5 to 185.5 days) hens started laying at a similar age and earlier than B1 (184 days), A2 (192 days), and B2 (194 days) hens. From AFE to 64 weeks, %Lay was the highest in the A1 line (69.7%), lowest in the B1 (45.3%) and B2 (48.8%) line, and between 56.9 and 64.8% in PS breeder hens. The PS eggs tended to have higher fertility, HOF, and HOS, and less embryonic mortality compared to PL eggs. Negative and low heterosis for AFE was observed in PS eggs, while positive heterosis for fertility, HOF, and HOS was generally observed in four-way hybrid eggs. The highest heterosis for the 64-week cumulative egg number was observed in A3 × A2 hens. Our study results show that mating of B1 × B2 males with A3 × A2 females seems more favorable in terms of higher egg or chick production. However, more knowledge is also needed for the overall efficiency of each PS, including the final performance of its hybrids.

Research Note: Divergent selection for breast muscle ultimate pH affects egg quality traits in broiler breeders.

Two divergently selected broiler lines were created by selection for low (pHu-) or high (pHu+) Pectoralis major ultimate pH (pHu) in order to better understand the molecular mechanisms underlying meat quality traits in broilers and are also unique genetic resources reflecting low and high glycogen levels in chicken muscle. The present study aimed to reveal the correlated phenotypical changes of egg quality traits in broiler breeders from the 2 divergent lines at the 14th generation. Birds were reared on littered floor system until 18 wk of age and in individual cages up to 42 wk. Individual egg production was recorded daily from age at first egg to 42 wk. External (egg weight: EW and shape index: SI), internal (albumen height: AH, Haugh unit: HU, yolk index: YI, and yolk color: YC), and shell (shell percentage: ESP, thickness: EST and strength: ESS) characteristics of eggs in pHu- and pHu+ lines were measured in all eggs for 4 consecutive days at 26, 27, 28, 30, 31, 32, 41, and 42 wk of age. The pHu- line had significantly higher egg percentage than pHu+ (55.9 and 49.1%, respectively). The EW in pHu- line (57.2 g) was significantly lower than in pHu+ (59.0 g) and increased with age in both lines. The mean ESP, EST and ESS were lower in the pHu+ eggs compared to the pHu- line. ESP and EST decreased mainly from 26 to 27 wk of age and they had a stable trend with advancing age in the remaining weeks. AH and YI were lower in pHu- line eggs than in pHu+. YC was more intense and HU higher in pHu+ eggs than pHu- in pre-peak and peak laying period. In conclusion, these results showed that a divergent selection for muscle energy metabolism has led to correlated responses on internal and external egg quality traits and suggest that the production of good-quality eggs may be impaired in broiler breeders with low energy reserves.

Effects of varying group sizes on performance, body defects, and productivity in broiler chickens.

This study aimed to determine the changes in the performance, welfare, and productivity level of broiler chickens reared at various group sizes (GS3000, GS4000, GS6000, and GS20 000) under intensive field conditions. The study was carried out according to a randomized block design with four different group sizes (GS) in three trials. Weekly body weights (BWs) were determined randomly in 150 individuals from each GS group. Feed intake (FI), feed conversion ratio (FCR), and European production efficiency factor (EPEF) were determined for each GS treatment. Body defects (footpad dermatitis, FPD, hock burn, HB, and the breast burn, BB) were measured randomly in 150 chickens (75 male and 75 female) from each group using a visual scoring system with a 0-3 scale. At 1 and 2 weeks of age, GS3000 broilers had similar BW to GS6000 and higher than GS4000 and GS20 000. However, this situation changed at 6 weeks of age and the male chickens in GS6000 became heavier than in GS3000, GS4000 and GS20 000 ( P   =  0.007). No differences in mean values of temperature, humidity, air velocity and litter moisture levels were observed among GS treatments. GS3000 and GS4000 chickens had significantly lower levels of FPD, HB, and BB than chickens reared in GS6000 and GS20 000 ( P   <  0.001). The EPEF values from highest to lowest were 425.8, 404.5, 358.8, and 354.0 in the GS6000 GS3000, GS4000, and GS20 000 groups, respectively. In conclusion, our study results showed that rearing in groups of 6000 broilers had both better performance and higher overall productivity than other groups but tended to show more severe body defects.

The effects of intermittent feeding and cold water on welfare status and meat quality in broiler chickens reared under daily heat stress.

This study was aimed to determine the effects of feeding type (ad libitum: AF and intermittent: IF) and water temperature (normal: NW and cold: CW) treatments on welfare status and meat quality in fast-growing broiler chickens reared under daily heat stress between 22 and 42 days of age. The chickens' panting rate and rectal temperature were determined at 4, 5, and 6 weeks of age and twice a week in 3 female and 3 male chickens in each pen. Welfare traits such as foot pad dermatitis (FPD), hock burn (HB), breast burn (BB), and leg problems (LP) were examined individually at 42 days of age. At day 43, 3 male and 3 female chickens per pen were randomly selected and slaughtered after an 8-h fasting period; pH and color (lightness (L*), redness (a*), and yellowness (b*)) of breast and thigh meat were determined. AF × C W chickens had significantly higher panting rates at all ages than the other groups (P < 0.05). While FPD and LP were not affected by feeding type and water temperature treatments, interaction effects on HB and BB were found significant (P < 0.05). The HB and BB levels were the lowest in AF × NW chickens (P < 0.05). While treatments did not change to any color traits in breast meat (P > 0.05), interactions significantly affected the yellowness (b*) value in the thigh (P < 0.05). In conclusion, management practices such as IF and CW in fast-growing broilers could not completely reduce the undesirable effects of heat stress on some welfare and meat quality traits, and in some cases, even caused more negativity.

The effects of natural mating and artificial insemination on reproductive traits of 1-and 2-year-old domestic Turkish geese.

The aim of this study was to assess the sperm quality traits of 1- and 2-year-old ganders and the reproduction traits of 2-year-old domestic Turkish geese in natural mating (NM) and artificial insemination (AI) conditions. The study comprised 72 two-year-old females, 12 one-year-old, and 12 two-year-old ganders. Thirty-six female geese were mated naturally (18 with 1-year-old ganders, 18 with 2-year-old ganders); the remaining thirty-six were inseminated artificially (18 with 1-year-old ganders, 18 with 2-year-old ganders). Twenty-four ganders were separated into groups (12 for NM; 12 for AI). The male:female ratio was 1:3 for NM and AI groups. Egg production, broodiness, fertility and hatching traits were determined in female geese, sperm quality traits such as semen volume, sperm concentration, sperm quality factor (eSQF: ejaculated semen SQF; dSQF: diluted semen SQF), sperm motility, and sperm morphological traits in ganders. The insemination method and gander's age did not affect egg production, AI geese showed significantly more broodiness than NM groups as the breeding months progresses (p < 0.05). Fertility was higher in the groups containing 2-year-old ganders than in those 1-year-old ganders, and NM groups compared to AI (p < 0.05). The insemination method significantly affected semen volume, sperm concentration, eSQF, sperm motility, total live sperm, normal sperm, macro-cephalic sperm, and dead sperm percentages in ganders (p < 0.05).Managing females in the NM system with ganders was able to partially suppress the broodiness behavior, possibly due to synchronization of pair-bond behaviors. Greater fertility was achieved with 2-years-old AI ganders, which had lower dSQF compared to 1-year-old NM ganders. This is a good indication that only SQF is not sufficient to achieve sustainable-desired fertility, and sexual experience is also an important factor.

Effect of light intensity and stocking density on the performance, egg quality, and feather condition of laying hens reared in a battery cage system over the first laying period.

The present study aimed to determine the effects of varying light intensity (high 121.8, medium 57.4 and low 11.9 lux) and stocking density (high 552.3, medium 736.3, and low 1104.5 cm2 cage floor area per hen) treatments on the performance, egg quality, and certain feather condition traits of Lohmann-Brown hens reared in a battery cage system between 20 and 40 weeks of age. Body weight was determined individually at 19 weeks and at 50% yield age (sexual maturity). Feed intake, egg yield, egg weight, and feed conversion ratio were determined weekly. Feather condition was also evaluated individually at 40 weeks of age. Hens reared under high light intensity and low stocking density reached sexual maturity and peak yield earlier than others. The highest body weight was determined for hens reared under high light intensity (1536.6 g), while the lowest in the medium light intensity group (1461.2 g). Hens reared under high and medium light intensity showed higher egg yield than those reared in low intensity (120.5, 120.0 and 112.8 eggs, respectively). In addition, hens reared at low and medium stocking density had higher egg yield than high density (119.7, 120.7, and 112.9 eggs, respectively). Hens reared under low (61.6 g) and medium (61.0 g) light intensity produced heavier eggs than hens in high light intensity (59.6 g). While feed intake was not affected in any treatment, hens reared at low and medium stocking density had a better feed conversion ratio than hens at high density (2.19, 2.20, and 2.40, respectively). Our study results showed that a sustainable production is possible by maintaining the welfare-performance balance when 50-60 lux light intensity and 700-800 cm2 cage floor area per hen are provided.

The effect of intermittent feeding and cold water on performance and carcass traits of broilers reared under daily heat stress.

OBJECTIVE: This study aimed to determine the effect of intermittent feeding and cold water on performance and carcass traits in broiler chickens between 4 to 6 wk of age exposed to daily high temperature. METHODS: Broilers were assigned to four treatment groups according to a 2×2 factorial design between 22 to 42 d of age (80 broilers per treatment, 4 replications). Broilers were divided into two main groups as feeding type (ad-libitum [AL] and intermittent [IF] for 6 h daily) and sub-groups as water temperature (normal [NW], 24.9°C and cold [CW], 16.4°C). Heat treatment was applied between 11.00 to 17.00 h daily between 22 to 42 d of age. RESULTS: Live weight at 6th wk was not affected by feeding type and water temperature, but the live weight was significantly higher in IF chickens at the 5th wk (p<0.05). Average weekly gain of IF broiler chickens were higher compared to AL group at 4, 5, and 6 wk of age (p<0.05). Although feeding type did not affect feed intake in 4 and 5th wk, feed intake was higher in IF chickens at 6th wk (p<0.01). In addition, feeding type and water temperature did not affect feed conversion ratio and interactions were not significant (p>0.05). Water temperature had no significant effect on heart, liver, gizzard, and abdominal fat percentages (p>0.05). CONCLUSION: It is concluded that IF increased the average weekly gain in chickens reared under daily heat stress for 6 h between 22 to 42 d of age. IF in hot environmental conditions slightly increased performance without adversely affecting health, welfare, and physiological traits, whereas CW implementation had no significant effect on performance. It can also be said that IF suppresses a sudden increase in body temperature depending on age and live weight.